Their is a problem with that. First that is 15 years old and is not open source (it is just source open). This was for educational purposes and first ever implementation of the common language runtime. It was a prove of concept project.
"Shared Source." I.e. Never look at that code, ever. Just pretend Rotor doesn't even exist. There are projects that will not have you (Mono) if you've read Rotor code.
Yeah, the problem is that MS decided to not really do cross-platform, despite having paid the technical cost and design. Thus dooming .NET to coming second place to the JVM as far as neat languages and tech goes.
